Method for operating a drivetrain for a work machine, drivetrain for a work machine, and work machine

Abstract

A method for operating a drive train for a mobile machine, including a first electric motor driving a working drive of the mobile machine via a first transmission arrangement, and a second electric motor driving a propulsion drive of the mobile machine via a second transmission arrangement, wherein a rotational speed of the second electric motor increases during a shifting operation of the second transmission arrangement out of a higher gear stage into a lower gear stage, and wherein during the shifting operation, a drive connection is established via a first clutch between the first electric motor and the propulsion drive, such that the propulsion drive is driven by the first electric motor during the shifting operation.

The invention claimed is: 
     
       1. A method for operating a drive train for a mobile machine, comprising:
 driving, via a first electric motor, a working drive of the mobile machine via a first transmission arrangement; and 
 driving, via a second electric motor, a propulsion drive of the mobile machine via a second transmission arrangement; wherein:
 a rotational speed of the second electric motor increases during a shifting operation of the second transmission arrangement out of a higher gear stage into a lower gear stage, 
 during the shifting operation, a drive connection is established via a first clutch between the first electric motor and the propulsion drive, such that the propulsion drive is driven by the first electric motor during the shifting operation, and 
 the first electric motor drives the propulsion drive only to the extent that a power output difference between a power requirement of the propulsion drive and a power output which can be provided by the second electric motor during the shifting operation is bridged. 
 
 
     
     
       2. The method as claimed in  claim 1 ,
 wherein the shifting operation is carried out under power. 
 
     
     
       3. The method as claimed in  claim 1 , wherein the first electric motor drives the propulsion drive and the working drive at the same time during the shifting operation. 
     
     
       4. The method as claimed in  claim 1 , wherein a providable power output of the first electric motor is configured to synchronize clutch halves of a clutch which is assigned to the lower gear stage. 
     
     
       5. The method as claimed in  claim 1 , wherein a providable power output of the second electric motor is configured to increase a rotational speed of the second electric motor. 
     
     
       6. The method as claimed in  claim 1 ,
 wherein the first electric motor drives the propulsion drive only to the extent that a power requirement of the working drive can be met completely during the shifting operation. 
 
     
     
       7. A drive train for a mobile machine, comprising:
 a first electric motor; 
 a second electric motor; 
 a first transmission arrangement; and 
 a second transmission arrangement, wherein:
 the first electric motor and the first transmission arrangement are assigned to a working drive of the mobile machine, 
 the second electric motor and the second transmission arrangement are assigned to a propulsion drive of the mobile machine, 
 a drive connection is established via a first clutch between the first electric motor and the propulsion drive, 
 a rotational speed of the second electric motor increases during a shifting operation of the second transmission arrangement out of a higher gear stage into a lower gear stage, 
 during the shifting operation, the drive connection is established via the first clutch between the first electric motor and the propulsion drive, such that the propulsion drive is driven by the first electric motor during the shifting operation, and 
 the first electric motor drives the propulsion drive only to the extent that a power output difference between a power requirement of the propulsion drive and a power output which can be provided by the second electric motor during the shifting operation is bridged. 
 
 
     
     
       8. The drive train as claimed in  claim 7 , wherein the first electric motor and the second electric motor are arranged in a common housing. 
     
     
       9. The drive train as claimed in  claim 7 , wherein the second transmission arrangement can be power-shifted via a plurality of gear stages. 
     
     
       10. The drive train as claimed in  claim 7 , wherein the working drive comprises at least one hydraulic pump providing hydraulic power which can be adjusted via a swash angle. 
     
     
       11. The drive train as claimed in  claim 7 , wherein the drive train is configured to:
 drive, via the first electric motor, the working drive of the mobile machine via the first transmission arrangement; and 
 drive, via the second electric motor, the propulsion drive of the mobile machine via the second transmission arrangement. 
 
     
     
       12. A mobile machine, comprising the drive train as claimed in  claim 8 . 
     
     
       13. A method for operating a drive train for a mobile machine, comprising:
 driving, via a first electric motor, a working drive of the mobile machine via a first transmission arrangement; and 
 driving, via a second electric motor, a propulsion drive of the mobile machine via a second transmission arrangement; wherein:
 a rotational speed of the second electric motor increases during a shifting operation of the second transmission arrangement out of a higher gear stage into a lower gear stage, 
 during the shifting operation, a drive connection is established via a first clutch between the first electric motor and the propulsion drive, such that the propulsion drive is driven by the first electric motor during the shifting operation, and 
 during the shifting operation, the second electric motor is temporarily disconnected from the propulsion drive. 
 
 
     
     
       14. The method of  claim 13 , wherein the second electric motor is temporarily disconnected from the propulsion drive via a second clutch during the shifting operation. 
     
     
       15. The method of  claim 14 , wherein the second electric motor is connected to the propulsion drive via a third clutch after the shifting operation.